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Interview with Robert Koch of Robert Koda about the Robert Koda Takumi K-15 preamplifier NEW

This took quite some time to finalise, but its finally ready. Matej Isak interviews Robert Koch of Robert Koda about the Robert Koda Takumi K-15 preamplifier and his brand. Enjoy…


  • edited August 2015
    I feel much privileged to be invited to upgrade my ‘001’ serialed Takumi K15 to K15Extreme and it was delivered to me last week with the entire chasis replaced with a new one! Obviously I still have the honor to keep the serial of ‘001’ on this new born flagship of the Takumi family.

    First impression: midrange to high, much improved in the resolution compared to K15 piercing into sky high seemingly without an end. Leading and trailing transient becomes extremely intact and fast. The entire 3-dimensionality has been much deepened into the z-axis if one is sitting in the ‘king seat’ for listening. On my favourite cello music, Schubert Arpeggione played by Maurice Gendron, K15Ex brings much textual and spatial resolution between the cello and the piano as though Gendron and Inoue are playing in front of me! In the past, I may have used ‘roller coaster’ to describe a rising surge and deep diving of the tempo but compared to what I am hearing, there was a track leading the roller coaster while I am now flying freely in the sky in a guilder!

    More to come after more burning in….

    Once again, Robert, you have exceeded what I believe was already unprecedented!!

  • Another pic...
  • This is quite a surprise. How can Robert improve the already marvellous K15? I also just received the "upgrade service" for existing K15 user email from AE. I am really curious about this one as I have long been Robert's fan since K10, which is still a great preamp now since its introduction 6 years ago.
  • That is quite neat! I thought Robert is going to throw us a new amp. My dear Marvel, you are really a preamp freak! How many preamps do you have? How do you compare K15EX to the benchmark? And what exactly is your benchmark. I really want to dig into your insight.
  • 最近社會氣氛十分之悶煩,想不到今晩突然Marvel兄長公告了巨匠K15EX, 真的有點驚喜。Robert Koda在港已經大有忠誠支持者,而事實上從他的K10開始致今,實在不停在進步。我十分期朌Marvel兄長的詳細報告。
  • Hi Marvel,

    May you tell us how is the K15Extreme different internally from the K15?

    BTW I heard that the 2nd or 3rd Cessaro Air One passive autoformer preamp coming to HK will be yours.
    Eager to know how the two diff top preamps differ sonically.


  • The following is from Robert's simulation result:

    The following is a spectrograph. There are 7 singular frequencies fed into the amplifier and they are represented by 7 sharp vertical spikes that each go up to about "-95" on the vertical scale on the left hand side.

    Both K-15 and the K15EX show the 7 singular frequencies. Now looking lower down towards the bottom, you can see a whole bunch of shorter vertical lines, mostly in red. Each of those lines represents a new frequency the amplifier has generated (Distortion) and the height of each line indicates the strength of each distortion.

    You will see that there is also a little bit in green (becoming yellow if it coincides with red). The green graph is for K15EX and the red graph is for the original K-15. This is NOT an illustration. It is a high powered simulation.

    The results show K15EX does substantially better than the K15.
    On average, not only are the intensity of each distortion reduced by about 30 times but also K15EX has fewer of them to begin with.
  • The entire true balance differential circuit board inside the EX is brand new. Technically speaking, it is a completely new preamplifier. I have already sent upgrade notice to all existing K15 users.
  • It is good to have a new party here! A question for Marvel, had you adjusted your sub settings with respect to the new presence of K15EX?
  • Raymond, I have taken out the sub for the time being in order for me to understand more about the performance of K15Ex across the frequency spectrum that I can hear from my alpha2.

    The noise platform is much lower than K15 and it may even be lower than Lars Monica. My benchmark is Air-1 by Cessaro which I heard in Ralph's place which is: No noise can be audible under the 107db sensitive Cessaro Beethoven.


  • Marvel

    Thanks for the effort of bringing us the latest report of all type of new electronics.

    Without the RACH sub, isn't it is very difficult for you to evaluate? Your RACH sub settings were done with respect to the Lars suite when Ralph visited your home.

    A simple swap between the Monica and the Takumi K15 does not bring meaningful result until you reset all the sub parameters. Taking off the RACH to compare is hard because LARS Monica must always work better with type 2.

    You can only describe the characteristic of some frequencies but integration is another story.
  • Robert Koch official announcement of the Robert Koda Takumi K-15 EX preamplifier:
  • Marvel,

    Can you share more about K15EX? The world is falling apart now. The appearance of K15EX brightens up my day very much.

    I am a hard core trinity fans. But I also respect Robert's work tremendously because I once owned the outstanding K10
  • Longinus, the setting of the Rach is mainly to ensure the phasing of the bass waves generated by the subwoofer and the bass drivers of the main speaker. This being one factor, another factor is the adjustment on the output of the active amp inside the Rach relative to the output of the main amp (in my case Lars Type 2). Changing the preamp may change the setting of the latter which I need to start to readjust. I have bought a pair of Vertere Pulse R interconnect to run from the preamp to Rach attempting to match the speed of propagation from pre to power which I am using a pair of Vertere HB. I even choose to take the same length for the interconnect.

    On the first day of listening, I told PT that the output gain of the K15Ex appears to be higher than K15 but after cross checking with Robert, this is not the case. Although the hypothesis was wrong, the listening experience cannot be wrong. Awaiting for more technical spec to be announced, I believe the dynamic range has been widened in the Ex version leading to less dynamic compression.

    (to be cont'd...)
  • Marvel

    Are there any follow up report on the K15EX?
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